JPH0545449A - Radar apparatus and target tracking method - Google Patents

Abstract

PURPOSE:To obtain a radar apparatus which has excellent detecting performance and can track a plurality of targets within the same range gate. CONSTITUTION:Pluralities of coherent integrators 7, detectors 8, non-coherent integrators 9 and threshold detectors 10 are connected to range gates (1-M) 6, respectively. All outputs of the threshold detectors are connected to a distance-error detector (detecting means) 11. Furthermore, a range-gate controlling circuit 12 and a range-gate generator 13 are connected. A display device 14 for displaying the output of the range gate generator 13 is connected. Since the detections with a plurality of combinations of the number of the coherent integrators the number of the non-coherent integrators are performed at the same time, the targets can be judged at the maximum detecting probability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar device using pulse integration.

[0002]

2. Description of the Related Art Conventionally, as a radar device of this type, for example, a reference, GVMorris: ■ Airborne Pulsed Doppler Ra
dar, Artech House, Inc. (1988) and the Institute of Electronics, Information and Communication Engineers, edited by Takashi Yoshida, "Radar Technology", (198
Some are shown in 7). FIG. 5 is a block diagram showing the configuration of a conventional radar device. In the figure, 1 is a transmitter. Reference numeral 2 is a transmission / reception switch which receives the transmission signal output from the transmitter 1 and outputs the transmission signal. Reference numeral 3 is a transmission / reception antenna, which receives a transmission signal output from the transmission / reception switch 2 and outputs a transmission radio wave. Further, the transmission / reception antenna 3 inputs a reception radio wave and outputs a reception signal. The transmission / reception switch 2 receives the reception signal output from the transmission / reception antenna 3 and outputs the reception signal. Reference numeral 4 denotes a receiver, which receives the reception signal output from the transmission / reception switch 2 and outputs a complex video signal. An A / D converter 5 inputs the complex video signal output from the receiver 4 and outputs a digital signal. 6 is a range gate, and the A /
The digital signal output from the D converter 5 is input and the digital signal is output. Reference numeral 7 denotes a coherent integrator, which inputs the digital signal output from the range gate 6 and outputs a digital signal as a result of coherent integration. Reference numeral 8 denotes a wave detector, which inputs the digital signal which is the output of the coherent integrator 7 and outputs a digital signal as a result of detection. Reference numeral 9 denotes a noncoherent integrator, which inputs the digital signal output from the detector 8 and outputs a digital signal as a result of performing noncoherent integration. Reference numeral 10 is a threshold detector which inputs the digital signal which is the output of the non-coherent integrator 9 and outputs a result indicating whether or not it is detected as a target. Reference numeral 11 is a distance error detector, which is an output of the threshold detector 10 to which a result of whether or not it is detected as a target is input, and a result of detection of a change in the range gate in which the following target is present is output. .. 1
Reference numeral 2 is a range gate control circuit, and the distance error detector 1
The result of detecting the change of the range gate in which the following target exists, which is the output of 1, is input, and the range gate number in which the target exists is output. Reference numeral 13 denotes a range gate generator, which inputs the range gate number with the target, which is the output of the range gate control circuit 12, and outputs a control signal for processing the output of the range gate with the target. A control signal for processing the output of the range gate having the target, which is the output of the range gate generator 13, is fed back and input to the range gate 6. Reference numeral 14 is an indicator, and the range gate control circuit 1
The range gate number where the target exists, which is the output of 2, is input, and tracking information (distance data, tracking history) is displayed.

The conventional radar apparatus is constructed as described above, and the transmission signal is radiated from the transmitter 1 to the outside via the transmission / reception switch 2 and the transmission / reception antenna 3, and the signal reflected by the target is the transmission / reception antenna 3, It enters the receiver 4 as a reception signal via the transmission / reception switch 2, the reception signal is converted into a complex video signal, and then converted into a digital signal by the A / D converter 5. This digital signal is divided into M range gates 6 whose range gate width is determined by the pulse width, and is input to the coherent integrator 7 for each range gate to perform Nf times of coherent integration (pre-detection integration). Then, the wave is detected by the wave detector 8, and the non-coherent integrator 9 performs non-coherent integration (post-detection integration). When the output signal of the non-coherent integrator 9 exceeds the threshold level set in the threshold detector 10, it is detected as a target. All the outputs of the threshold detector 10 are input to the distance error detector 11 to detect the change of the range gate where the following target exists. The output of the distance error detector 11 is input to the range gate control circuit 12, the range gate number at which the target exists is output, and is input to the range gate generator 13 and the display 14. The range gate generator 13 outputs a control signal for processing the output of a specific range gate. The output of the range gate generator 13 is fed back to process the output of the range gate 6 where the target exists,
The display device 14 displays tracking information (distance data, tracking history).

[0004]

In the conventional radar apparatus as described above, the coherent integration number and the noncoherent integration number are fixed, and the detection probability is limited.
Further, there is a problem that even if there are a plurality of targets in the same range gate, they can be detected only as a single target.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a radar device having good detection performance and capable of following a plurality of targets within the same range gate.

[0006]

In a conventional radar device, a coherent integrator, a detector, and a noncoherent detector are provided for each of a plurality of range gates whose range gate width is determined by the pulse width. The radar apparatus and the target tracking method according to the first and second aspects of the present invention have a plurality of range gates whose range gate width is determined by the pulse width. Each has a plurality of coherent integrators, a plurality of detectors, a plurality of non-coherent integrators, and a plurality of threshold detectors. The calculation is performed with different ratios of.

Further, in the conventional radar device, the distance error detector that follows the target does not have the function of following a plurality of targets within the same range gate.
In the radar device according to the invention, a plurality of ranges are set for a received signal, and a plurality of integration processes in which the ratio of the number of integration of coherent integration and the number of integration of non-coherent integration are different for each range are integrated. Means, the threshold means for respectively inputting the plurality of signals subjected to the integral processing, and performing the threshold processing, and the same by detecting the number of targets in the range from the plurality of the threshold processed signals. A detection means having a function of following a plurality of targets within the range is provided.

[0008]

In the radar apparatus and the target tracking method according to the first and second aspects of the present invention configured as described above, each range gate has a plurality of coherent integrators, and a plurality of detectors.
Since a plurality of noncoherent integrators and a plurality of threshold detectors are provided, detection by a plurality of combinations of the coherent integration number and the noncoherent integration number is performed simultaneously, and the detection probabilities differ depending on the combination. The detection performance is improved because the points are used.

Further, in the radar device according to the third invention,
A plurality of targets in the same range gate can be tracked by utilizing the fact that the combination of the coherent integration number and the non-coherent integration number that maximizes the detection probability is different depending on the target.

[0010]

【Example】

Example 1. FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 1 is a transmitter. Reference numeral 2 denotes a transmission / reception switch, which inputs a transmission signal output from the transmitter 1,
Output the transmission signal. Reference numeral 3 is a transmission / reception antenna, which receives a transmission signal output from the transmission / reception switch 2 and outputs a transmission radio wave. Further, the transmission / reception antenna 3 inputs a reception radio wave and outputs a reception signal. The transmission / reception switch 2 receives the reception signal output from the transmission / reception antenna 3 and outputs the reception signal. Reference numeral 4 denotes a receiver, which receives the reception signal output from the transmission / reception switch 2 and outputs a complex video signal.
An A / D converter 5 inputs the complex video signal output from the receiver 4 and outputs a digital signal. Reference numeral 6 is a range gate, which inputs the digital signal output from the A / D converter 5 and outputs the digital signal. 7
Is a coherent integrator, which inputs the digital signal output from the range gate 6 and outputs a digital signal as a result of the coherent integration. Reference numeral 8 denotes a wave detector, which inputs the digital signal which is the output of the coherent integrator 7 and outputs a digital signal as a result of detection. 9 is a non-coherent integrator, and the detector 8
The digital signal which is the output of is input and the digital signal of the result of performing non-coherent integration is output. 10
Is a threshold detector, to which the digital signal which is the output of the noncoherent integrator 9 is input, and the result of whether or not it is detected as a target is output. Reference numeral 11 denotes a distance error detector which is an example of a detecting means, which inputs the result of whether or not it is detected as a target, which is the output of the threshold detector 10, and detects the change of the range gate in which the following target exists. The output result is output. Reference numeral 12 denotes a range gate control circuit, which is an output of the distance error detector 11 and which receives a result of detection of a change in the range gate in which a target is following and outputs a range gate number in which the target is present. It Reference numeral 13 denotes a range gate generator, which inputs the target number or range gate number where the target exists, which is the output of the range gate control circuit 12, and outputs the range gate where the target number or target exists and the range gates on both sides thereof. A control signal for processing is output. A control signal for processing the output of the range gate generator 13, which is the output of the range gate generator 13, and the outputs of the range gates on both sides of the target is fed back to the range gate 6. Reference numeral 14 is a display, which inputs the target number or range gate number where the target exists, which is the output of the range gate control circuit 12, and displays tracking information (distance data, tracking history).

Reference numeral 20 is a receiving means or a receiving step for receiving a received signal having a predetermined pulse width, 21 is a range dividing step for dividing the received signal received in the receiving step into a plurality of ranges based on the pulse width, and 22 is a range. Pre-detection integration step of performing a plurality of integrations with different integration numbers in each of the ranges divided in the division step, 23 is a detection step of detecting each signal integrated in the pre-detection integration step, and 24 is a pre-detection integration step. A post-detection integration step of performing a plurality of integrations on a signal detected in the detection step with a predetermined number of integrations corresponding to a plurality of integrations of, and 25 is a threshold level for a signal integrated in the post-detection integration step. A threshold detection step for detecting a change in the range in which the target being tracked is present and the number of targets is changed by using the outputs of a plurality of threshold detectors. The control means 27 for detecting and following these targets sets a plurality of ranges with respect to the received signal, and a plurality of ranges having different ratios of the number of coherent integration and the number of non-coherent integration are set for each range. Integrating means for performing integration processing, and 28 is a threshold means for performing threshold value processing by inputting each of the plurality of signals subjected to the integration processing.

In the tracking radar device configured as described above, the transmission signal is radiated from the transmitter 1 through the transmission / reception switch 2 and the transmission / reception antenna 3 to the outside, and the signal reflected at the target is the transmission / reception antenna 3, It enters the receiver 4 as a reception signal via the transmission / reception switch 2, the reception signal is converted into a complex video signal, and then converted into a digital signal by the A / D converter 5. This digital signal is divided into M number of range gates 6 whose range gate width is determined by the pulse width, and is input to P number of coherent integrators 7 for each range gate, respectively, and 1 to P times (1, 2, 4,
8, 16, ..., P / 4, P / 2, P) after coherent integration (pre-detection integration) is performed, the wave is detected by the wave detector 8, and further input to the non-coherent integrator 9. P ~ 1 time (P, P / 2, P / 4, ..., 16, 8,
4, 2, 1) non-coherent integration (post-detection integration) is performed. Here, the total number of pulse hits is P, and when the coherent integration number is N and the noncoherent integration number is K, the relational expression P = N × K is satisfied. When the output signal of the non-coherent integrator 9 exceeds the threshold level set in the threshold detector 10, it is detected as a target. All outputs of the threshold detector 10 obtained for each range gate are input to the distance error detector 11 to follow the target. The output of the distance error detector 11 is input to the range gate control circuit 12, the target number and the range gate number at which the target exists are output, and are input to the range gate generator 13 and the display 14. The range gate generator 13 outputs a control signal for processing the output of a specific range gate. Range gate generator 1
The output of No. 3 is fed back to process the output of the range gate in which the target exists and the range gates on both sides of the target, and the display 14 displays tracking information (distance data, tracking history).

Now, the principle of determining the optimum number N _P of coherent integration will be described. FIG. 2 shows an example of the relationship between the SN ratio (signal power to noise power ratio after coherent integration) and the coherent integration number N, where the SN ratio per pulse of the received signal is a certain value. When there is no fluctuation in the received signal (received signal Doppler spectrum bandwidth BW≈0) as in 3 (a), the SN ratio after coherent integration is improved by increasing the number N of coherent integrations. In this case, it is known that, under the given false alarm probability P _N , the coherent integral number N _{P at which} the detection probability P _D becomes maximum becomes equal to the total pulse hit number P.

On the other hand, when the received signal fluctuates as shown in FIG. 3B due to the fluctuating target, the SN ratio of the coherent integration number cannot be improved even if the coherent integration number N is increased to a certain value or more. .. In FIG. 2, α and β are SNs after coherent integration when the received signal has fluctuations.
The ratio shows the value of the coherent integration number N that cannot be improved, and can be expressed by 1 / BW.

Next, FIG. 4 is a diagram for explaining the operation of the non-coherent integrator, in which the horizontal axis represents power and the vertical axis represents the probability density function Pdf. A shows the distribution of noise N, B shows the distribution of signal S + noise N before non-coherent integration, and C shows the distribution of signal S + noise N after coherent integration. Although the case of K = 1, 2, and 4 is shown among C, the mountain shape projects upward as the integration number K increases. L indicates a threshold level, and the shaded portion on the right side of L is a signal detected above the threshold level. P _N is the false alarm probability and P _D is the detection probability. As shown by the arrow in the figure, when the non-coherent integration is performed, the distribution B changes to the distribution C, so the detection probability P _D
Will increase. Moreover, the detection probability P _D increases as the integration number K increases.

Here, in FIG. 5, the given false alarm probability P is given.
Under _N , when the S / N ratio per pulse of the reception signal is set to a certain value and the reception signal Doppler spectrum bandwidth is changed, the detection probability P _D versus the coherent integration number N (the noncoherent integration number is P / (Which can be represented by N).

The circles and the triangles indicate the detection probabilities of the targets having different received signal Doppler spectrum bands. In the case of the circles, the coherent integration number = P /
8. The detection probability is maximum when the number of non-coherent integrations = 8, and the number of coherent integrations = P /
2. When the number of noncoherent integrations = 2, the detection probability becomes maximum. As shown in this figure, it can be seen that the detection probability changes depending on the ratio of the coherent integration number and the noncoherent integration number. When the target received signal Doppler spectrum bandwidth is different, the combination of the coherent integration number and the noncoherent integration number that maximizes the detection probability differs depending on the target. Since the tracking radar device configured as shown in FIG. 1 detects all combinations of the coherent integration number and the noncoherent integration number, the coherent integration number and the noncoherent integration number are different from those of the conventional radar device. The detection performance is improved as compared with the case where it is fixed.

Next, the operation of the detecting means will be described. The distance error detector 11, which is an example of a detecting unit, follows a target according to the flowchart of FIG. Here, T is a variable for controlling the loop, To is a target number detected in one loop, Tn is a target number output from the distance error detector 11, and Tr is a target number. It is the number of detected ranges to follow. In step 15a, the previous T
Substituting n, it is determined in step 15b whether T is 0 or not. When T is 0, the range gate number M is substituted for T in step 15c, and the process proceeds to step 15d. The reason for substituting M is that all range gates (M) are set as the range gates to follow when the previously output target number is zero (or when the initial value is 0). T if T is not 0
= Tr indicates the number of ranges that T follows, and in step 15e, 0 is substituted for Tn and Tr, and step 15
Proceed to d. In step 15d, 1 is subtracted from T, and the detection results obtained from the range gate to be tracked in step 15f and the range gates on both sides of the range gate are fetched as data,
In step 15g, it is determined whether or not the target is detected. When the target is detected, the range gate to be followed is processed in step 15h, and the process proceeds to step 15i. When the target is not detected, the range gates on both sides of the range gate to be followed are processed in step 15j, and the process proceeds to step 15i. In step 15i, it is determined whether the range gate has been processed. If it is not the processed range gate, the process proceeds to step 15k. If it is a processed range gate, the process proceeds to step 15m. The adjacent targets detected as the result of the combination of the integrals in step 15k are regarded as the same target, the number of targets detected as a result is set to To, and the process proceeds to step 151. Step 1
In 5l, 1 is added to Tr, To is added to Tn, and it is determined in step 15m whether T is 0 or not. If T is not 0, the process returns to step 15d to repeat the loop. T is 0
In the case of, the range gate number with the target and the target number Tn are determined in step 15n, and the process ends.

FIG. 7 shows an example in which two targets within the same range gate are detected. In the figure,
The shaded area is the area to be processed, and the circle indicates that the target has been detected. When the range gate number to be tracked is m, the range gates with range gate numbers m-1 and m + 1 are also processed, and three range gates are processed. As a result of processing, in this example, X1
And the target X is detected from X2, the target Y is detected from Y1, Y2 and Y3, and two targets are detected.
This is because the magnitude of the fluctuation (BW) of the signals reflected from the targets X and Y is different, so that the ratio of the coherent integration number and the non-coherent integration number at which the detection probability becomes maximum as shown in FIG. Take advantage of different things.

As described above, in this embodiment, in the radar device using pulse integration, the range gate width is adjusted by the A / D converter for converting the received signal into a digital signal and the pulse width connected to the A / D converter. A plurality of range gates, a plurality of coherent integrators connected to the range gate, a detector connected to each of the coherent integrators, and a noncoherent integration connected to each of the detectors. Detectors, a threshold detector connected to each of the noncoherent integrators, and the outputs of multiple threshold detectors are used to detect changes in the range gate in which the target being followed and changes in the target number. And a distance error detector that follows those targets,
A range gate control circuit that outputs a target number or a range gate number where a target exists, and a range gate generator that outputs a control signal for processing the output of the specific range gate by the output of the range gate control circuit. The radar device having the above has been described.

In this embodiment, a radar device using radio waves is described, but it can also be used as a target position detecting device using light waves.

Further, in this embodiment, the radar device for following the target is described, but it may be used as a search radar device.

[0023]

Since the present invention is constructed as described above, it has the following effects.

In the radar device and the target tracking method configured as described above, the detection performance is improved because detection is performed by a plurality of combinations of the coherent integration number and the noncoherent integration number at the same time. Further, it is possible to follow a plurality of targets within the same range gate for the same reason as above.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between the SN ratio after coherent integration and the number of coherent integrations.

FIG. 3 is a diagram showing fluctuation of a signal reflected from a target.

FIG. 4 is a diagram showing an action of non-coherent integration.

FIG. 5 is a diagram showing a relationship between a detection probability and a coherent integration number in Embodiment 1 of the present invention.

FIG. 6 is a flowchart showing the operation of the distance error detector according to the first embodiment of the present invention.

FIG. 7 is a diagram showing an operation result of the distance error detector according to the first embodiment of the present invention.

FIG. 8 is a block diagram showing a conventional radar device.

[Explanation of symbols]

 1 transmitter 2 transmission / reception switch 3 transmitting / receiving antenna 4 receiver 5 A / D converter 6 range gate 7 coherent integrator 8 detector 9 non-coherent integrator 10 threshold detector 11 range error detector 12 range gate control circuit 13 range Gate generator 14 Display

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[Procedure amendment]

[Submission date] October 14, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 3

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

Reference numeral 20 is a receiving means or a receiving step for receiving a received signal having a predetermined pulse width, 21 is a range dividing step for dividing the received signal received in the receiving step into a plurality of ranges based on the pulse width, and 22 is a range. Pre-detection integration step of performing a plurality of integrations with different integration numbers in each of the ranges divided in the division step, 23 is a detection step of detecting each signal integrated in the pre-detection integration step, and 24 is a pre-detection integration step. A post-detection integration step of performing a plurality of integrations on a signal detected in the detection step with a predetermined number of integrations corresponding to a plurality of integrations of, and 25 is a threshold level for a signal integrated in the post-detection integration step. threshold detection step of detecting whether exceeds 26 uses the outputs of the plurality of threshold detectors, change the range of the presence of the target that is to follow And a control means for detecting changes in the number of targets and following those targets, 27 sets a plurality of ranges for the received signal, and the number of coherent integrations and the number of non-coherent integrations are set for each range. Integrating means for performing a plurality of integration processings having different ratios, and 28 is a threshold means for inputting the plurality of signals subjected to the integration processing and performing a threshold processing.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

Now, the principle of determining the optimum number N _P of coherent integration will be described. Figure 2 is when the value in the S / N ratio per 1 pulse of the received signal, S /
FIG. 3 shows an example of the relationship between the N ratio (signal power to noise power ratio after coherent integration) and the number N of coherent integrations, and there is no fluctuation in the received signal as shown in FIG. 3A (received signal Doppler spectrum band). In the case of the width BW≈0), the S / N ratio after coherent integration is improved by increasing the number N of coherent integrations. In this case, it is known that, under the given false alarm probability P _N , the coherent integral number N _{P at which} the detection probability P _D becomes maximum becomes equal to the total pulse hit number P.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

On the other hand, when the received signal fluctuates as shown in FIG. 3 (b) due to the fluctuating target, the S / N ratio of the coherent integration number is improved at a certain value or more even if the coherent integration number N is increased. I can't measure it. When α and β in FIG. 2 each have a fluctuation in the received signal, S after coherent integration is used.
The / N ratio indicates the value of the coherent integration number N that cannot be improved, and can be expressed by 1 / BW.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction content]

Next, FIG. 4 is a diagram for explaining the operation of the non-coherent integrator, in which the horizontal axis represents power and the vertical axis represents probability density.
It is. A shows the distribution of noise N, B shows the distribution of signal S + noise N before non-coherent integration, and C shows the distribution of signal S + noise N after coherent integration. Although the case of K = 1, 2, and 4 is shown among C,
The larger the integration number K, the more the mountain shape projects. L
Indicates the threshold level, and the shaded area on the right side of L is the signal detected above the threshold level. P _N is the false alarm probability and P _D is the detection probability. As shown by the arrow in the figure, when the non-coherent integration is performed, the distribution B changes to the distribution C, so that the detection probability P _D increases. Moreover, the detection probability P _D increases as the integration number K increases.

[Procedure Amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

[0017] ○ Although signs and △ marks are those each received signal Doppler spectrum bandwidth shows the detection probability of the different target, in the case of ○ mark, coherent integration number = P /
8. The detection probability is maximum when the number of non-coherent integrations = 8, and the number of coherent integrations = P /
4 , the non-coherent integration number = 4 , the detection probability becomes maximum. As shown in this figure, it can be seen that the detection probability changes depending on the ratio of the coherent integration number and the noncoherent integration number. When the target received signal Doppler spectrum bandwidth is different, the combination of the coherent integration number and the noncoherent integration number that maximizes the detection probability differs depending on the target. Since the tracking radar device configured as shown in FIG. 1 detects all combinations of the coherent integration number and the noncoherent integration number, the coherent integration number and the noncoherent integration number are different from those of the conventional radar device. The detection performance is improved as compared with the case where it is fixed.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

Next, the operation of the detecting means will be described. The distance error detector 11, which is an example of a detecting unit, follows a target according to the flowchart of FIG. Here, T is a variable for controlling the loop, To is a target number detected in one loop, Tn is a target number output from the distance error detector 11, and Tr is a target number. It is the number of detected ranges to follow. In step 15a, the previous T
Substituting r , it is determined in step 15b whether T is 0 or not. When T is 0, the range gate number M is substituted for T in step 15c, and the process proceeds to step 15d. The reason for substituting M is that all range gates (M) are set as the range gates to follow when the previously output target number is zero (or when the initial value is 0). T if T is not 0
= Tr indicates the number of ranges that T follows, and in step 15e, 0 is substituted for Tn and Tr, and step 15
Proceed to d. In step 15d, 1 is subtracted from T, and the detection results obtained from the range gate to be tracked in step 15f and the range gates on both sides of the range gate are fetched as data,
In step 15g, it is determined whether or not the target is detected. When the target is detected, the range gate to be followed is processed in step 15h, and the process proceeds to step 15i. When the target is not detected, the range gates on both sides of the range gate to be followed are processed in step 15j, and the process proceeds to step 15i. In step 15i, it is determined whether the range gate has been processed. If it is not the processed range gate, the process proceeds to step 15k. If it is a processed range gate, the process proceeds to step 15m. The adjacent targets detected as the result of the combination of the integrals in step 15k are regarded as the same target, the number of targets detected as a result is set to To, and the process proceeds to step 151. Step 1
In 5l, 1 is added to Tr, To is added to Tn, and it is determined in step 15m whether T is 0 or not. If T is not 0, the process returns to step 15d to repeat the loop. T is 0
In the case of, the range gate number with the target and the target number Tn are determined in step 15n, and the process ends.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

FIG. 2 is a diagram showing the relationship between the S / N ratio after coherent integration and the number of coherent integrations.

[Procedure Amendment 9]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure Amendment 10]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

[Procedure Amendment 11]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 7

[Correction method] Change

[Correction content]

[Figure 7]

Claims (3)

[Claims] 1. A radar device using pulse integration having the following elements: (a) receiving means for receiving a received signal having a predetermined pulse width; (b) a pulse width of the received signal received by the receiving means. A plurality of range gates which are divided into a plurality of ranges on the basis of each of the ranges, and each of which receives a received signal of each range, (c) a plurality of coherent integrators connected to the range gate, Detector, (e) non-coherent integrator connected to each of the detectors, (f) threshold detector connected to each of the non-coherent integrators, (g) using outputs of the plurality of threshold detectors Then, the control means for detecting the change in the range in which the target is following and the change in the number of the targets, and following the targets. 2. A target tracking method including the following steps: (a) a receiving step of receiving a plurality of received signals having a predetermined pulse width, (b) a plurality of received signals received in the receiving step based on the pulse widths. A range division step of dividing into ranges, (c) a pre-detection integration step of performing a plurality of integrations having different integration numbers in each of the ranges divided in the range division step, and (d) integration in the pre-detection integration step. A detection step of detecting the respective signals, (e) a post-detection integration step of integrating the signals detected in the detection step with a predetermined number of integrations corresponding to a plurality of integrations in the pre-detection integration step, (f) For the signal integrated in the post-detection integration step,
A threshold detection step of detecting a threshold level, (g) using the output from the above threshold detection step to detect a change in the range in which the target being tracked exists and a change in the number of targets, and to track those targets Control process. 3. A radar device having the following elements: (a) A plurality of ranges are set for a received signal, and a plurality of ratios of coherent integration and non-coherent integration are different for each range. Integration means for performing the integration processing of (b), threshold means for respectively inputting the plurality of signals subjected to the integration processing, and (c) a plurality of signals subjected to the threshold processing, within the range. A detection means for detecting the number of targets.